The strategy of combining computations that can throw exceptions
by bypassing bound functions
from the point an exception is thrown to the point that it is handled.

Is parameterized over the type of error information and
the monad type constructor.
It is common to use Either String as the monad type constructor
for an error monad in which error descriptions take the form of strings.
In that case and many other common cases the resulting monad is already defined
as an instance of the MonadError class.
You can also define your own error type and/or use a monad type constructor
other than EitherString or EitherIOError.
In these cases you will have to explicitly define instances of the Error
and/or MonadError classes.